1. Field of the Invention
The invention relates to track-tensioning equipment for automotive purposes, in particular for military armored vehicles or earthwork machinery, the equipment furthermore being also applicable to tensioning chains, belts, endless belts and the like.
2. Related Art
In a track-equipped vehicle, i.e., a vehicle fitted with caterpillar treads, each track is guided by and runs on rollers resting on the ground, further running on a drive sprocket at one end of the vehicle and a tail pulley at the other vehicle end also serving to tension the track, for which purpose it cooperates with displacement means for the two mutually opposite directions for increasing and decreasing the track tension.
As a rule, the tensioning tail pulley rests on a crankshaft driven by mechanical or hydraulic means, for instance by a mechanical screw and gear configuration controlling the angular position of the crankshaft or by a hydraulic actuator with a straight-moving piston hinging by fittings on the vehicle body and on a crankshaft arm.
Such known equipment incurs many drawbacks. The hydraulic means are mounted outside the vehicle body and therefore are vulnerable to damage and susceptible to the ambient environment. Moreover, the stresses transmitted to the crankshaft bearings are very high. As regards the mechanical means, they may be mounted inside the vehicle body, but on the other hand they are complex and adjusting the track tensioning is time-consuming and also must take place while the vehicle is stopped on flat terrain and must be carried out by personnel outside the vehicle, and it is comparatively of low accuracy. Again these mechanical means are rigid and if subjected to high stresses may break at once or after a delay (in particular if soil jams between the track and its rollers), and there is substantial danger that the tracks will come off.